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Free Resources (free + resource)

Distribution by Scientific Domains
Engineering40%

Selected Abstracts

Optimal use of solar collectors for residential buildings

INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 11 2001
Stig-Inge GustafssonArticle first published online: 5 JUN 200
Abstract Solar radiation is an abundant free resource which may be used in the form of solar heated water. This is achieved in solar collectors which, unfortunately, are expensive devices and, further, the warm water must be stored in accumulators,items which also cost money. This paper shows how we have optimized the situation for a block-of-flats in Sweden. In order to find this point we have used the minimum life-cycle cost (LCC) concept as a criterion. The best solution is therefore found when that cost finds its lowest value. It is also examined under which conditions solar collectors are part of the optimal solution and further it is calculated what happens if this optimal point is abandoned, i.e. how much will the LCC increase if other than optimal solutions are chosen. LCC optimization for multi-family buildings almost always results in a heating system with low operating costs such as district heating or dual-fuel systems where a heat pump takes care of the base load and an oil boiler the peak. The installation cost must, however, be kept to a reasonable level. Expensive solar panel systems are therefore normally avoided if the lowest LCC shall be reached, at least for Swedish conditions. This is so even if the solar system has a very low operating cost. For buildings where the only alternative energy source is electricity, solar collectors seem to be on the rim of profitability, i.e. for an energy price of about 0.6 SEK kWh,1. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Improving node behaviour in a QoS control environment by means of load-dependent resource redistributions in LANs,

INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 4 2005
Bernd E. Wolfinger
Abstract An important means to guarantee an acceptable quality of service in networks with real-time communication requirements is the reservation of resources at connection setup time. However, such reserved resources, e.g. transmission bandwidth, may be unused as a consequence of the variations in the actual resource demands. Therefore, a more efficient resource utilization is possible if communicating stations or end-users dynamically hand over some of the free resources temporarily to the other communication partners, e.g. of a ,broadcast network'. This paper concentrates on two fundamental problems of such a demand-based sharing of resources: on the one hand, estimation of the current resource requirement on the basis of load measurements is investigated and, on the other hand, we elaborate efficient algorithms for resource sharing respecting real-time requirements. The algorithms proposed for load estimation and for resource sharing are evaluated analytically with respect to their efficiency for worst-case, average-case and realistic load scenarios. Our approach suggested for resource and traffic management allows one to achieve significantly better utilization of network resources. Copyright © 2005 John Wiley & Sons, Ltd. [source]

RAS kite-marks free resources

ASTRONOMY & GEOPHYSICS, Issue 5 2007
Article first published online: 20 SEP 200
As part of its Education Programme, writes Andrew Morrison, the RAS is setting up a database of free resources to support teachers in delivering the astronomy, space and geophysics sections of the school curriculum. [source]

1 YouTube for Ultrasound Education

ACADEMIC EMERGENCY MEDICINE, Issue 2008
Michael Liao
The internet has many free resources that can be leveraged for education. We wish to present the use of two popular and free websites to more effectively disseminate educational cases and videos within a residency program and alumni network. Traditionally, sharing video was limited by cost, equipment, and technical challenges. YouTube and similar video sharing websites are attractive in that they allow free, permanent, and widely compatible hosting of videos. Realizing this potential we began using YouTube to share interesting and important video clips of emergency ultrasound cases, thus reaching a broader audience within our residency than possible during conference or tape review sessions. YouTube, however, doesn't allow extensive text and descriptions. We initially used email to convey the case details, however, to better organize and consolidate our cases, we turned to popular free webpage hosting sites like officelive.com and blogger.com. We chose officelive.com for its simplicity, free domain registration, and online web design interface. By using YouTube's ability to embed video onto any website, we were able to present case and video together on one page. All this for free and with common and easy to use online tools. Please visit emugweb.com to see what we have done. We believe that continued and innovative usage of these free internet tools can make our job as educators easier and at the same time offer a more organized and accessible format to our students. [source]